Effects of Mass Transfer Rate and its Expressions on Dynamics of Mass Transfer Operation

Abstract

In this paper, the dynamics with respect to mass transfer operation in a perfect mixing vessel is discussed. The transfer functions for the small change of concentrations or flow rates of input fluids are derived and the effects of residence time, stripping factor and number of transfer units, etc. on the dynamics are explained by using Bode diagrams. In addition, the limitation on the use of the mass transfer capacity coefficient, the Murphree efficiency and the height per transfer unit in unsteady state are discussed, and it is concluded that only the mass transfer capacity coefficient gives reasonable results whereas the Murphree efficiency must not be used as a constant.